In some cases, a flexible printed wiring board (FPWB) may be used to mutually connect devices and substrates incorporated in a housing of an electronic apparatus. Since the FPWB bends freely, FPWB connects the devices and substrates even if connectors are mounted with deviation within assembly tolerance when the devices and substrates are fixed in the housing. Since this FPWB is a thin film, the FPWB is passed through narrow gaps between the devices and substrates.
If the devices and substrates are assembled in the housing with high density, the distances between devices and substrates which are connected by the FPWB are reduced. If the connectors for mounting the FPWB are only slightly dislocated, in this case, in-plane and out-of-plane stresses, such as tensile, compression, and shear stresses, as well as bending and torsional stresses, which may act on the FPWB, increase.
Even after the FPWB is mounted in place, the relative positions of the connectors for the FPWB may be displaced when the housing receives an external force. Since the FPWB is not flexible to an in-plane dislocation along its surface, loads easily act on junctions between the FPWB and the connectors. If these loads are repeatedly applied to the FPWB, disengagement or disconnection may occur.
Even in the case of high-density assembly, manual operations are performed to fasten the devices and substrates in the housing and connect them by the FPWB. The FPWB is pinched in thickness direction or width direction at right angles to the direction of insertion when the FPWB is connected. If the FPWB is short, therefore, special care must be taken not to break it, thus complicating the connection operation.